Elasticity: Whether a Price Rise Pays
Elasticity measures how much the quantity demanded changes when the price changes, expressed as one percentage divided by another. Above one, demand is elastic and a price rise reduces revenue. Below one it is inelastic, and the same rise increases it.
How it works
It answers one question: if the price goes up, how much less do people buy? Everything else about the concept follows from that.
Both sides are percentages, which is what makes it comparable. Using percentages rather than units means the measure works the same way for a product costing pence and one costing thousands.
One is the dividing line. Above it, quantity moves more than price did — demand is elastic. Below it, quantity barely responds — demand is inelastic. At exactly one, the two changes offset.
That boundary is the whole practical content. If demand is inelastic, raising the price raises revenue, because you lose proportionally fewer customers than the price gained. If it is elastic, the same rise reduces revenue. A company that does not know which it faces is guessing at its own pricing.
Why an investor should care
“Pricing power” is this concept in investing vocabulary. When an analyst says a company can raise prices without losing volume, the claim being made is that demand for its product is inelastic. The economics word is older and more precise.
Two things soften demand. Available substitutes — if customers can switch easily they will — and time, because a rise absorbed this month may be designed around next year. Short-run inelasticity is common and long-run inelasticity is rare, which is why durable pricing power is worth so much.
It is fitted, not observed. Any figure comes from historical price and volume data, and it describes the range over which the price actually moved. Extrapolating beyond that range is where the concept gets misused.
In practice
It feeds the revenue line of a model. A discounted cash flow rests on assumed revenue, and assumed revenue rests on assumptions about price and volume that this concept governs.
The “volume” here is units of product, not volume on a chart. They share a word and nothing else, and conflating them is an easy mistake to make when the term arrives in a market context.
Customers respond slowly. Contracts run their term, habits persist, and alternatives take time to find — so a price rise this quarter shows its full effect several quarters later.
A large disruption does not move along the curve; it moves the curve. New entrants, regulation or a technology change alter the relationship rather than producing a new point on the old one.
It is not a market concept at all. It says nothing about the share price, nothing about timing, and nothing about where a stop belongs.
And acting on the conclusion has the usual price. A round trip on this site’s shared history is 2% of a median bar’s range, whatever the analysis behind it.
Testing pricing power without an economics degree
Look at what happened the last time the company raised prices. The annual reports will say, and the volume line in the same period says how customers answered. That comparison is a rough elasticity estimate and it takes twenty minutes.
Then ask the two questions that generate the answer. What could a customer switch to, and how long would switching take. A product with no near substitute and a high cost of changing has inelastic demand whatever the spreadsheet says, and one with an equivalent alternative a click away does not, however loyal the customers appear.
Watch for the difference between raising prices and being able to. Many companies have not tested it recently, and an untested belief is what most pricing-power claims actually rest on.
What elasticity is not
It is not volatility. Different measurement entirely.
It is not fixed. It changes with substitutes and time.
It is not observed. It is fitted to past data.
And it is not a trading signal. It informs a valuation.
When it fails
In a stable market the belief goes unexamined. Prices have not moved much, so nobody has learned whether customers would tolerate a rise, and the assumption sits in every model unchallenged until conditions force the experiment.
The second failure is extrapolating beyond the observed range. A relationship fitted to small price changes says nothing about a large one.
A third is confusing short-run with long-run. Customers adapt, and the adaptation is the point.
A fourth is measuring during a period when something else changed. A competitor’s exit, a shortage or a subsidy contaminates the estimate completely.
A fifth is applying an industry figure to one company. Brands within a category differ enormously.
And a sixth is treating pricing power as permanent. It is a position, and positions are attacked.
The original data
Of the 24,971 videos in research/search-study-corpus.jsonl, 1 has “elasticity” in the title, and it
has 319,166 views. “Valuation” appears in 7 at a median of 51,619 and “revenue” in the corpus barely at
all. The counts are in research/corpus-coverage.json, produced by site/measure_corpus.py.
One video, 319,166 views. That is six times the median of the seven valuation videos, from a single upload, for a concept most trading audiences would say belongs in an economics class. The demand is plainly there; the supply is one person who happened to make it.
The answer to that final question is: not yet, and the timing tells you why. Volumes holding through a single price rise is short-run behaviour, and short-run inelasticity is ordinary. Look again after the contracts renew and the substitutes have had time to appear — pricing power that survives that is worth paying for, and pricing power measured over one quarter is a hypothesis.
Related
Valuation is where this assumption ends up, underneath the revenue forecast. Revenue is the line it governs and the first one on the income statement. And discounted cash flow is the model most sensitive to getting it wrong.
This is an economics term and I nearly left it out, until I noticed I had been reaching for the idea constantly without the word. Every time I wondered whether a company could put its prices up without losing customers, I was asking about elasticity. Having the actual name for it made the question sharper, and made it obvious how rarely anyone answers it with evidence.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.